Constant dim light at night causes depression, and increases in the hippocampus of the number of tumor necrosis factor, tell us researchers from Ohio state University.
Scientists have called the "dim light" that brighter natural light of the moon 5 times. So, for example, can be considered the dim light of a lamp or the included screen TV, working in a dark room. The researchers, headed by Randy Nelson believe, chronic dim light at night can cause depression and affect biochemical processes in the brain.
By conducting experiments with hamsters, scientists have proven that light bulb bedtime interferes with proper secretion of the hormone melatonin, which gives a signal to the body that it is night. Half of laboratory animals slept in the dim light, another group of hamsters in complete darkness. 8 weeks after the start of the experiment, scientists have identified the first symptoms of depression in wards, sleeping in the dim light. In their brain changes occurred in the Department of the hippocampus. In this zone was reduced density of some of the structures that transmit messages from one cell to another. Scientists have concluded that the hippocampus plays a major role in the formation of depressive disorders.
The second cycle of the experiment, when in the brain, the animals were administered an antagonist of tumor necrosis factor (TNF), have shown that it also influenced the development of depression. Thus, American scientists have concluded that light at night leads to depression, and TNF plays a role here.
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Researchers insist, depressive changes are reversible if the return of the classic cycle of alternation of light and darkness. Scientists advise people to turn off at night nightlight and TV, as well as to sadarghat tight curtains. In addition, American doctors suggested that the increase in depression among American citizens is associated with increased exposure to light for residents at night. To confirm this hypothesis, you will need to spend some more research.